1. Field of the Invention
The present invention relates to a pair of eyeglasses. More particularly, the present invention relates to a pair of eyeglasses that can be attached to a visor of a cap.
2. Description of the Related Art
Eyeglasses and hats are often used for shielding from the sun when going out. Eyeglasses and hats are separate and thus must be carried separately. It is very inconvenient for a use wearing a pair of corrective eyeglasses to carry a pair of sunglasses.
Eyeglasses attachable to a visor of a cap have been proposed. A pair of eyeglasses of this type can be moved between an operative position for shielding from the sun and an inoperative position for clear vision.
FIGS. 7 and 8 of the drawings illustrate a pair of conventional eyeglasses attachable to a visor of a cap. The pair of eyeglasses includes a lens 1′, two engaging blocks 2′ (only one is shown) respectively on two sides of the lens 1′, and two clamping members 3′ (only one is shown). Each engaging block 2′ includes an end securely engaged with an associated side of the lens 1′. The other end of each engaging block 2′ includes a protrusion 21′ with a plurality of teeth 211′ on a circumference thereof. Each clamping member 3′ includes a first end that can be clamped to a side of a visor (not shown) of a cap (not shown). Each clamping member 3′ further includes a second end that has an engaging hole 31′ for receiving the protrusion 21′ of an associated engaging block 2′. A plurality of teeth 311′ are defined in an inner circumference defining the engaging hole 31′ and engage with the teeth 211′ of the protrusion 21′. The engaging block 2′ can be pivoted relative to the clamping member 3′ and then retained in place.
However, expansion of the circumferential wall defining the engaging hole 31′ is not easy such that a large force is required to turn the engaging block 2′, which is inconvenient to adjustment of the angular position of the lens 1′. Further, the teeth 211′ and 311′ wear out easily, leading to unreliable positioning of the engaging block 2′ relative to the clamping member 3′.